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Transmitter Capsule Disassembly and Refilling

Started by rp2813, May 03, 2014, 04:04:49 PM

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Matilo Telephones

#15
This is al very helpfull information, thanks TelePlay.

My ultrasonic cleaner is a cheap one of not very good quality. It was a gift so I'm not complaining.

I think it is because the frequency is a little to low. And it starts walking across the table when I turn it on.

Thanks BDM, I was seriously wondering if I could put the caps on the washing machine for a week. Perhaps that would also do the trick. Or use some other mechanical device.

Anyway, here are some technical drawings of the caps I'll be working on. I'll first see if I can open (and close) one without too much trouble.
Groeten,

Arwin

Check out my telephone website: http://www.matilo.eu/?lang=en

And I am on facebook too: www.facebook.com/matilosvintagetelephones

twocvbloke

The only transmitter I've pulled apart (more for curiosity's sake) was one of my GPO Transmitter Inset No. 16, it was crackly and under-performing, so I peeled it open, had a look, put all the carbon back in and closed it up as best I could, doesn't work any better than it did before though, but like I say I just did it to have a look inside rather than fix it, this was before I joined this forum too... :)

rp2813

I guess if you knew someone who worked at a paint store you could ask them to tape a capsule to a gallon of paint and send it through the shaker . . .
Ralph

LarryInMichigan

Many of my transmitters have a problem with static, not weakness.  The majority of my European ones have this problem.  I often connect a resistor in parallel with the transmitter to reduce the amount of current flowing through it and hence the amount of static, but this only helps to an extent.  Has anyone here found a way to fix the static problem?  I have a number of European phones which I would use if they wouldn't produce so much static.

Thank You

Larry

poplar1

Bruce Crawford used to replace Ericofon transmitters with T-1s---not original of course but that's how he got rid of the static.
"C'est pas une restauration, c'est une rénovation."--François Martin.

Matilo Telephones

Larry, I never have any trouble here with static. Not on local phones, and not on Ggerman, Belgian, English phones. Wasn't there a difference in the properties of the capacitors? Might that cause the sounds quality problems?
Groeten,

Arwin

Check out my telephone website: http://www.matilo.eu/?lang=en

And I am on facebook too: www.facebook.com/matilosvintagetelephones

LarryInMichigan

It may be that the higher DC line voltage here is too much for some European transmitters.

Larry

Matilo Telephones

Groeten,

Arwin

Check out my telephone website: http://www.matilo.eu/?lang=en

And I am on facebook too: www.facebook.com/matilosvintagetelephones

dsk

#23
Here in Norway, the typical line voltage are stated to be 48V but I have measured about 60 where i Lived in Oslo.
:-\ What may be of imortance are our automatic line current compensation, trying to keep the line current up to 39 milliamps.
Older Norwegian phones may sometimes get statics, these transmitters does always have the sound of moving sand inside when you shake them carefully. (of course it is carbon granulates). A shunting resistor are usually solving this, but it may be something in what Arwin said. In the us you use a different ringer/capacitor circuit, this may help filtering.  All my noisy transmitters are made in Antwerp.

Typical data for my line are here:  http://tinyurl.com/mec52et

dsk

twocvbloke

The GPO had issues with static with the Trimphone, and their solution was a varistor connected across the transmitter, so if there was too much current running across the transmitter, the varistor would heat up and absorb the excess preventing the "fried egg" sound that was common with that model... :)

Matilo Telephones

Hmmm, I think I have an article about the difference in electrical properties and causing loss of sounds quality between the T65 and international phonecalls to the US.

I'm trying to remember where I have this article.
Groeten,

Arwin

Check out my telephone website: http://www.matilo.eu/?lang=en

And I am on facebook too: www.facebook.com/matilosvintagetelephones

Matilo Telephones

Groeten,

Arwin

Check out my telephone website: http://www.matilo.eu/?lang=en

And I am on facebook too: www.facebook.com/matilosvintagetelephones

twocvbloke

Quote from: Matilo Telephones on May 06, 2014, 04:24:07 PM
Varistor = diode, right?


Varistor = Variable resistor, it changes it's resistance as it warms up, therefore directing unwanted current away from something that is sensitive to current... :)

http://en.wikipedia.org/wiki/Varistor

BDM

I still like my electric football game better. It could be the "F1s" vs the "T1s" in a game to the death. Bet the T1s win. Meanwhile repairing stuck granules ;D ;D
--Brian--

St Clair Shores, MI

dsk

#29
Quote from: BDM on May 06, 2014, 04:39:58 PM
I still like my electric football game better. It could be the "F1s" vs the "T1s" in a game to the death. Bet the T1s win. Meanwhile repairing stuck granules ;D ;D
That is a pretty good one, another is to take your capsules on a holiday, and drive some bus in Oslo's "hol(e)y" streets. 
According to one of our busdrivers (I live 1 hour bu bus from Oslo) The driving in the city kills the buses, and the rest are no trouble.  :) :) :)

dsk